1080/60i Footage image strobe in Europe
I'm working on a North American TV doc series, which covers luxurious high end products from around the world. We're using 3 Sony EX1 cameras for acquisition and 6 Avid Media Composer suites connected to a UNITY media engine in post.
Aside from the painful workflow to get footage into Avid, everything is working great and the footage is breath taking. Our problem is that footage shot overseas comes out with a serious lighting flicker on it. Anything shot indoors under artificial light or outside at night is affected. One camera man tried shooting at 1080/50i, which solved the strobing, but more than doubles the import time with all the transcoding that needs to happen in order to edit in a 60i project. It also results in an ugly stutter in the footage from the 5 repeated frames per second. I'm looking for an in camera setting that will correct this lighting flicker issue. We've tried stuff with flicker reduction on and off, but haven't had any concrete results. Has anyone else experienced this, or know a fix. |
The pulsing comes from the frequency or cycles of the lights in different countries. Set the shutter speed to 1/50 to match the 50Hz of PAL countries and 1/60 to match the 60 Hz of NTSC countries.
|
That's it exactly.
Quote:
Any rate...shoot it at 1/50th as per Rick's accurate advice. Best, Craig |
Shutter Speeds Vs Shutter Anlge
My shooter tells me that while shooting in 60i mode, a 1/50 shutter speed is not available, so he's been shooting at 1/100, which seems to reduce the flicker in the image, but does not completely eliminate it.
From my limited experience shooting on this camera, I remember seeing an option in the menu to toggle between shutter speeds, and shutter angles. Can anyone shed some light on this avenue for a possible solution? |
The camera man should be able to flick through the different shutter/angle or speeds displayed on the LCD while filming using the direct menu togglestick on the top of the camera. When Im faced with flicker from lights I just have the scene set up and scroll through the shutter speeds until the flicker disappears. For very static shopts with not much movement shutter off works well. In NTSC countries shutter off is 1/24th, for PAL its 1/25th I guess.
Ps, Angle a speed are just different names for same thing so 1/48 Shutter Speed is 180 degrees etc. |
Quote:
I'll check that tomorrow if you want. (be carefull at what i'm saying. I drink too much yesterday and am a bit away today) |
you can't have a 50th shutter at 60i as the shutter would be open longer than a field duration. Best to use 100th.
|
There is a flicker reduction filter in the EX1. Haven't tried it for this problem but the Z1 has much the same filter and it worked a treat shooting 60i with our 50Hz lighting.
Around the same time I had quite a bit of footage shot for us in the USA with Z1s at 50i and no flicker problem. On the other hand 24p under 50Hz lighting with a rolling shutter is an impossible problem. You don't get flicker, you get rolling bars. This could be what's happening with the EX1 in which case shutter speed might make little difference. Just remembered what could be the crucial difference, the Z1 is CCD. |
"You don't get flicker, you get rolling bars."
- Bob Grant This is a more accurate description of the problem we're having with the footage. It's not as dramatic as the solid bars you would see on a computer screen while shooting at a frame rate out of sync with the monitor's refresh rate. Its soft, wide, dark rolling bars, that create the strobe look on the video. We used Z1U cameras on season 1 of this same series two years ago, and shot all over Europe with no problems at all with the footage. I think you're on to something with this CCD vs CMOS idea. The rolling shutter could be the root of the problem, but I really don't know enough about how it works. |
Switch Display
If you could switch your display frequency to 50hz/60hz how it would behave?
Or is it happening in prograssive mode also? |
All times are GMT -6. The time now is 10:36 PM. |
DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network